package com.nongxiange.chapter2.helper;

import com.nongxiange.chapter2.util.CollectionUtil;
import com.nongxiange.chapter2.util.PropsUtil;
import org.apache.commons.dbcp2.BasicDataSource;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.omg.CORBA.DATA_CONVERSION;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Properties;

/**
 * Created by zendwang on 2018-02-06.
 */
public class DatabaseHelper {

    private static final Logger LOGGER = LoggerFactory.getLogger(DatabaseHelper.class);


    private  static  final QueryRunner QUERY_RUNNER = new QueryRunner();

    private static final ThreadLocal<Connection> CONNECTION_HOLDER;

    private static  final BasicDataSource DATA_SOURCE;
    static  {
        CONNECTION_HOLDER = new ThreadLocal<Connection>();
        Properties conf = PropsUtil.loadProps("config.properties");
        String driver = conf.getProperty("jdbc.driver");
        String url = conf.getProperty("jdbc.url");
        String username = conf.getProperty("jdbc.username");
        String password = conf.getProperty("jdbc.password");

        DATA_SOURCE = new BasicDataSource();
        DATA_SOURCE.setDriverClassName(driver);
        DATA_SOURCE.setUrl(url);
        DATA_SOURCE.setUsername(username);
        DATA_SOURCE.setPassword(password);
    }

    /**
     * 获取数据库连接
     */
    public static Connection getConnection() {
        Connection conn = CONNECTION_HOLDER.get();
        if(conn == null) {
            try {
                conn = DATA_SOURCE.getConnection();
            }catch (SQLException e) {
                LOGGER.error("get connection failure",e);
                throw new RuntimeException(e);
            }finally {
                CONNECTION_HOLDER.set(conn);
            }
        }

        return conn;
    }

    /**
     * 查询实体列表
     */
    public static  <T> List<T> queryEntityList(Class<T> entityClass,String sql,Object... params) {
        List<T> entityList;
        try {
            Connection conn = getConnection();
            entityList = QUERY_RUNNER.query(conn,sql,new BeanListHandler<T>(entityClass),params);
        }catch (SQLException e) {
            LOGGER.error("query entity list failure",e);
            throw new RuntimeException(e);
        }
        return entityList;
    }
    /**
     * 查询实体
     */
    public static  <T> T queryEntity(Class<T> entityClass,String sql,Object... params) {
        T entity;
        try {
            Connection conn = getConnection();
            entity = QUERY_RUNNER.query(conn,sql,new BeanHandler<T>(entityClass),params);
        }catch (SQLException e) {
            LOGGER.error("query entity failure",e);
            throw new RuntimeException(e);
        }
        return entity;
    }

    /**
     * 执行查询语句
     * @param sql
     * @param params
     * @return
     */
    public static List<Map<String,Object>> executeQuery(String sql,Object... params) {
        List<Map<String,Object>> result;
        try{
            Connection conn = getConnection();
            result = QUERY_RUNNER.query(conn,sql,new MapListHandler(),params);
        } catch (Exception e) {
            LOGGER.error("execute query failure",e);
            throw new RuntimeException(e);
        }
        return result;
    }

    /**
     * 更新
     * @param sql
     * @param params
     * @return
     */
    public static int executeUpdate(String sql,Object... params) {
        int rows = 0;
        try{
            Connection conn = getConnection();
            rows = QUERY_RUNNER.update(conn,sql,params);
        } catch (Exception e) {
            LOGGER.error("execute update failure",e);
            throw new RuntimeException(e);
        }
        return rows;
    }
    /**
     * 插入实体
     * @param entityClass
     * @param fieldMap
     * @param <T>
     * @return
     */
    public static <T> boolean insertEntity(Class<T> entityClass,Map<String,Object> fieldMap) {
        if(CollectionUtil.isEmpty(fieldMap)) {
            LOGGER.error("can not insert entity: fieldMap is empty");
            return false;
        }
        String sql = "INSERT INTO  " + getTableName(entityClass);
        StringBuilder columns = new StringBuilder("(");
        StringBuilder values = new StringBuilder("(");
        for (String fieldName : fieldMap.keySet()) {
            columns.append(fieldName).append(", ");
            values.append("?, ");
        }

        columns.replace(columns.lastIndexOf(", "),columns.length(),")");
        values.replace(values.lastIndexOf(", "),values.length(),")");

        sql += columns + " VALUES "+ values;


        Object[] params = fieldMap.values().toArray();

        return executeUpdate(sql,params) == 1;

    }
    /**
     * 更新实体
     * @param entityClass
     * @param id
     * @param fieldMap
     * @param <T>
     * @return
     */
    public static <T> boolean updateEntity(Class<T> entityClass,long id,Map<String,Object> fieldMap) {
        if(CollectionUtil.isEmpty(fieldMap)) {
            LOGGER.error("can not update entity: fieldMap is empty");
            return false;
        }
        String sql = "UPDATE " + getTableName(entityClass) + " SET ";
        StringBuilder columns = new StringBuilder();
        for (String fieldName : fieldMap.keySet()) {
            columns.append(fieldName).append("=?, ");
        }
        sql += columns.substring(0,columns.lastIndexOf(", ")) + " WHERE id=?";

        List<Object> paramList = new ArrayList<Object>();
        paramList.addAll(fieldMap.values());
        paramList.add(id);

        Object[] params = paramList.toArray();

        return executeUpdate(sql,params) == 1;

    }
    /**
     * 删除实体
     * @param entityClass
     * @param id
     * @param <T>
     * @return
     */
    public static <T> boolean deleteEntity(Class<T> entityClass,long id) {
        String sql = "DELETE FROM "+ getTableName(entityClass) + " WHERE id=?";
        return executeUpdate(sql,id) == 1;
    }

    /**
     * 执行SQL文件
     */
    public static void  executeFile(String filePath) {
        InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream(filePath);
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        try {
            String sql;
            while ((sql=reader.readLine())!=null) {
                DatabaseHelper.executeUpdate(sql);
            }
        } catch (IOException e) {
            LOGGER.error("execute sql file failure",e);
            throw  new RuntimeException(e);
        }
    }

    private  static  String getTableName(Class<?> entityClass) {
        return entityClass.getSimpleName().toLowerCase();
    }
}
